The patch titled
oom: /proc/<pid>/oom_score treat kernel thread honestly
has been added to the -mm tree. Its filename is
oom-proc-pid-oom_score-treat-kernel-thread-honestly.patch
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------------------------------------------------------
Subject: oom: /proc/<pid>/oom_score treat kernel thread honestly
From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
If a kernel thread is using use_mm(), badness() returns a positive value.
This is not a big issue because caller take care of it correctly. But
there is one exception, /proc/<pid>/oom_score calls badness() directly and
doesn't care that the task is a regular process.
Another example, /proc/1/oom_score return !0 value. But it's unkillable.
This incorrectness makes administration a little confusing.
This patch fixes it.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/base.c | 5 +++--
mm/oom_kill.c | 13 +++++++------
2 files changed, 10 insertions(+), 8 deletions(-)
diff -puN fs/proc/base.c~oom-proc-pid-oom_score-treat-kernel-thread-honestly fs/proc/base.c
--- a/fs/proc/base.c~oom-proc-pid-oom_score-treat-kernel-thread-honestly
+++ a/fs/proc/base.c
@@ -428,7 +428,8 @@ static const struct file_operations proc
#endif
/* The badness from the OOM killer */
-unsigned long badness(struct task_struct *p, unsigned long uptime);
+unsigned long badness(struct task_struct *p, struct mem_cgroup *mem,
+ nodemask_t *nodemask, unsigned long uptime);
static int proc_oom_score(struct task_struct *task, char *buffer)
{
unsigned long points = 0;
@@ -437,7 +438,7 @@ static int proc_oom_score(struct task_st
do_posix_clock_monotonic_gettime(&uptime);
read_lock(&tasklist_lock);
if (pid_alive(task))
- points = badness(task, uptime.tv_sec);
+ points = badness(task, NULL, NULL, uptime.tv_sec);
read_unlock(&tasklist_lock);
return sprintf(buffer, "%lu\n", points);
}
diff -puN mm/oom_kill.c~oom-proc-pid-oom_score-treat-kernel-thread-honestly mm/oom_kill.c
--- a/mm/oom_kill.c~oom-proc-pid-oom_score-treat-kernel-thread-honestly
+++ a/mm/oom_kill.c
@@ -139,8 +139,8 @@ static bool oom_unkillable_task(struct t
* algorithm has been meticulously tuned to meet the principle
* of least surprise ... (be careful when you change it)
*/
-
-unsigned long badness(struct task_struct *p, unsigned long uptime)
+unsigned long badness(struct task_struct *p, struct mem_cgroup *mem,
+ const nodemask_t *nodemask, unsigned long uptime)
{
unsigned long points, cpu_time, run_time;
struct task_struct *child;
@@ -150,6 +150,8 @@ unsigned long badness(struct task_struct
unsigned long utime;
unsigned long stime;
+ if (oom_unkillable_task(p, mem, nodemask))
+ return 0;
if (oom_adj == OOM_DISABLE)
return 0;
@@ -351,7 +353,7 @@ static struct task_struct *select_bad_pr
if (p->signal->oom_adj == OOM_DISABLE)
continue;
- points = badness(p, uptime.tv_sec);
+ points = badness(p, mem, nodemask, uptime.tv_sec);
if (points > *ppoints || !chosen) {
chosen = p;
*ppoints = points;
@@ -482,11 +484,10 @@ static int oom_kill_process(struct task_
if (child->mm == p->mm)
continue;
- if (oom_unkillable_task(p, mem, nodemask))
- continue;
/* badness() returns 0 if the thread is unkillable */
- child_points = badness(child, uptime.tv_sec);
+ child_points = badness(child, mem, nodemask,
+ uptime.tv_sec);
if (child_points > victim_points) {
victim = child;
victim_points = child_points;
_
Patches currently in -mm which might be from kosaki.motohiro@xxxxxxxxxxxxxx are
origin.patch
acpi-fix-unused-function-warning.patch
mm-use-memdup_user.patch
oom-check-pf_kthread-instead-of-mm-to-skip-kthreads.patch
oom-pf_exiting-check-should-take-mm-into-account.patch
oom-introduce-find_lock_task_mm-to-fix-mm-false-positives.patch
oom-dump_tasks-use-find_lock_task_mm-too.patch
oom-improve-commentary-in-dump_tasks.patch
oom-dump_tasks-use-find_lock_task_mm-too-dump_tasks-use-find_lock_task_mm-too-fix.patch
oom-give-current-access-to-memory-reserves-if-it-has-been-killed.patch
oom-avoid-sending-exiting-tasks-a-sigkill.patch
oom-filter-tasks-not-sharing-the-same-cpuset.patch
oom-sacrifice-child-with-highest-badness-score-for-parent.patch
oom-sacrifice-child-with-highest-badness-score-for-parent-protect-dereferencing-of-tasks-comm.patch
oom-sacrifice-child-with-highest-badness-score-for-parent-fix.patch
oom-select-task-from-tasklist-for-mempolicy-ooms.patch
oom-select-task-from-tasklist-for-mempolicy-ooms-add-has_intersects_mems_allowed-uma-variant.patch
oom-select-task-from-tasklist-for-mempolicy-ooms-introduce-find_lock_task_mm-to-fix-mm-false-positives-fix.patch
oom-enable-oom-tasklist-dump-by-default.patch
oom-avoid-oom-killer-for-lowmem-allocations.patch
oom-extract-panic-helper-function.patch
oom-remove-special-handling-for-pagefault-ooms.patch
oom-move-sysctl-declarations-to-oomh.patch
mm-rename-try_set_zone_oom-to-try_set_zonelist_oom.patch
oom-remove-constraint-argument-from-select_bad_process-and-__out_of_memory.patch
oom-fold-__out_of_memory-into-out_of_memory.patch
mm-use-for_each_online_cpu-in-vmstat.patch
mempolicy-reduce-stack-size-of-migrate_pages.patch
mempolicy-reduce-stack-size-of-migrate_pages-fix.patch
vmscan-zone_reclaim-dont-call-disable_swap_token.patch
vmscan-recalculate-lru_pages-on-each-priority.patch
vmscan-tracing-add-trace-events-for-kswapd-wakeup-sleeping-and-direct-reclaim.patch
vmscan-tracing-add-trace-events-for-lru-page-isolation.patch
vmscan-tracing-add-trace-event-when-a-page-is-written.patch
vmscan-tracing-add-a-postprocessing-script-for-reclaim-related-ftrace-events.patch
vmscan-kill-prev_priority-completely.patch
vmscan-simplify-shrink_inactive_list.patch
vmscan-remove-unnecessary-temporary-vars-in-do_try_to_free_pages.patch
vmscan-set-up-pagevec-as-late-as-possible-in-shrink_inactive_list.patch
vmscan-set-up-pagevec-as-late-as-possible-in-shrink_page_list.patch
vmscan-update-isolated-page-counters-outside-of-main-path-in-shrink_inactive_list.patch
oom-dont-try-to-kill-oom_unkillable-child.patch
oom-oom_kill_process-doesnt-select-kthread-child.patch
oom-make-oom_unkillable_task-helper-function.patch
oom-oom_kill_process-needs-to-check-that-p-is-unkillable.patch
oom-proc-pid-oom_score-treat-kernel-thread-honestly.patch
oom-kill-duplicate-oom_disable-check.patch
oom-move-oom_disable-check-from-oom_kill_task-to-out_of_memory.patch
oom-cleanup-has_intersects_mems_allowed.patch
oom-remove-child-mm-check-from-oom_kill_process.patch
oom-give-the-dying-task-a-higher-priority-fix.patch
oom-multi-threaded-process-coredump-dont-make-deadlock.patch
reiser4.patch
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